Valve structure for rock drills



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Patented July 6, 1926.

Unirse marais tirar GUSTAVE M. NELL, OF CLEVELAND, OHIO. ASSIGNOR TO THE CLEVELAND ROCK DRILL COMPANY, OF CLEVELAND, OHO.

VALVE STRUCTURE FOR ROCK DRLLS.

Application filed November The present invention is directed to im-v provements in valve structures for rock drills.

The primary object of the invention is to provide novel means for locking the valve stem aga-inst accidental rotation, and at the same time permitting the valve to be easily and quickly disassembled for inspection.

A further object of the invention is to provide means for cushioning the movement of the valve during its reciprocation. It is well known that in drillsof this type the valve is rapidly reciprocated and during this reciprocation the ends thereof strike the end caps of the casing, and to cushion the impact of blows upon the respective caps, means are provided for yieldably holding the caps in their operative positions.

Vith these and other objects in view, as will appear as the description proceeds, the invention consists in the novel features of construction, combination of elements, and arrangement of parts hereinafter to be fully described, and particularly pointed out in the appended claim.

In the accompanying drawing:

Figure 1 is a longitudinal sectional view through the device.

Figure 2 is an end view of the valve casing.

Figure 3 is a similar view of the other end of the same.

Referring to the drawing 1 designates the cylinder of a rock drill in which is mounted for reciprocation the hammer 2. Mounted upon the cylinder 1 is a valve casing 3 having a longitudinal chamber 4 into which motive fluid is introduced through the port 5. The motive fluid, after being properly distributed by the valve 6 mounted for reciprocation in the chamber 4, is conducted to the hammer chamber 7 for reciprocating the hammer 2, as is customary. rlhe valve 6 is of the spool type and is provided with a. longitudinal aX- ially arranged bore 9. Since no claim is to be made for the specific construction of the valve 8 in this application, it is not thought lnecessary to give a detailed description of' the operation thereof.

It will be observed that the chamber 4 extends through the casing 3, and in order to close the o en ends thereof after the valve 6 has been p aced in said chamber, caps 10 and 11 are provided for engagement in the rea, 1922. serial No. 599,949.

spective open ends, as clearly shown in Fig. 1 of the drawing.

The caps 10 and 11 are of suoli dimensions to closely lit the ends of the chamber 4, and in order to limit the movement thereof inwardly they are provided with flanges 12 and 13, respectively. These flanges are of such construction that they not only limit the inward movements of the caps, but cooperate with the cylinder in such manner that they are held positively against rotation. l

The iange 12 of the cap 10 is provided with a lug 14, which is adapted to engage the longitudinal groove 15 formed in the cylinder 1, and when thus engaged it will be obvious that the flange 12, and thus the cap 10 is held against rotation, but may be readily removed upon sliding the same outwardly. The cap 11 has its flange 18 provided with a shallow recess 16, which is adapted to interlock with the lug 17 formed on the cylinder 1, thereby holding the cap 11 against rotation, but permitting the same to be conveniently removed when desired. The cap 11 is further provided with a cavity 18 in which is formed a seat 19, the purpose of which will appear later.

A longitudinal bore 2O is formed through the cap 11, and has its outer end opening into the cavity 18. It is necessary that the caps 10 and 11 be held firmly seated in the open ends of the chamber 4, and to accomplish this in a simple and efiicient manner, the cap 10 is provided: with an integral inwardly directed stem 21. r1`his stem is of such length as to pass through the bore 20 of the cap 11 and have its outer end projected beyond said cap, said stem being threaded for a certain distance of its length,

and engaged on the threaded portion is a nut 22 in which is formed a seat 23, the purpose of which will later appear. This stem of course passes through the axial bore 9 of the valve 6, and since the valve is mounted for reciprocation in the chamber 4 it necessarily follows that said valve slides upon the stem as its reciprocates.

A coil springl 24 encircles the threaded end of the stem 21, and has its inner helix provided with a head 25 adapted to engage in the seat 19, while the head 26 formed upon its outer helix engages in the seat 23 of the nut 22, as clearly illustrated in Fig. 1 of the drawing. Thus it ,vill he seen that upon manipulating,- the nut E22 in one direction that the spring` Qft will be compresse( to desired degree to hold the caps 10 and ll properlvv seated in the open ende of the ehamher 4, and owing` to the prefaenee ot' the hends Q5 and 26 accidental rotation of the nut QQ is prevented.

It is a Well known tact that rock drills of the pereussive type are iqulu'eeted to Considerable vihration when operating', and conSeqnentlY the valve parte4 lieeonie loose, which when unnoticed zillleets the elinieienev of the drill. This det'eet is overcome. in the present invention hy interloeliing` the @apn 10 and ll, reopeetivelj;r` und the evlindef. through the medium ot the lug lil. and groove 13 and the, recess 1G and lug 1T.

llt will 'further he observed that impact ot the liilovrsot the valve incident to Striking the respective caps duringiite reeiproeation ivill he cushioned owing to the presence of the Coil spring Zet, which will permit `slight. sliding movement o'i the respeetive caps.

llvhat is claimed is:

The combination vvith a Cylinder, of a easing carried thereby, a valve mounted for reeiproeatioii therein and having au uxial here, caps fitting directly in the ends ot the easing. one eap having an integral Stem whichr passes through said bore and the other Cap, Said evlinder having a relatively long longitudinal groove and lug disposed, refipeetiveljf, adjacent the endeY ot the canine'. Said cups: having. respeetivelji, :i peripherdl lug' and resse-1'` Yfor Slidahlv :ind detnehehle interlocking engagement. re-Speetivelv, with the groove and lug ot' the c vlinder` and n'ieans e gag'ed with one end ot' the stem for hol y both caps vieldzihlv engaged in the ende o't the easing.

In testimony whereof I have he'euiitu Set my hand.

GUSTAVE M. NELL. 

